RESUMO
A series of 146 primary and metastatic neoplasms of the CNS were studied with a panel of monoclonal and polyclonal antibodies. The purpose of the study was to evaluate whether immunohistochemistry can help in the differential diagnosis and facilitate a more precise classification of CNS tumors. Neoplastic cells in glial tumors (astrocytomas, ependymomas, oligodendrocytomas) reacted strongly with GFAP. Immunoreactivity with antibodies to neurofilaments helped to distinguish neuronal tumors. Keratin was always positive in metastatic carcinomas, while vimentin positivity characterized mesenchymal differentiation. Other markers such as LCA, S-100, alpha-1-antichymotrypsin, factor VIII, CEA and EMA were variably expressed by tumor cells providing information about cell differentiation and functional status.